His recipe (from Time)

“One quart cream, one quart milk, one dozen tablespoons sugar, one pint
brandy, 1/2 pint rye whiskey, 1/2 pint Jamaica rum, 1/4 pint sherry —
mix liquor first, then separate yolks and whites of eggs, add sugar to
beaten yolks, mix well. Add milk and cream, slowly beating. Beat whites
of eggs until stiff and fold slowly into mixture. Let set in cool place
for several days. Taste frequently.”

* Per Time, if you want to create the recipe try using a dozen eggs